System and method for sensing oil quality

ABSTRACT

A system for measuring the state of degradation of cooking oil in a deep fryer is provided. The system includes at least one fryer pot and a loop of piping fluidly connected thereto for selectively allowing flow of oil from the at least one fryer pot into the loop and for selectively allowing the cooking oil to return to said at least one fryer pot from the loop. A pump urges the flow of cooking oil through the loop of piping and selectively to urge oil to return to the at least one fryer pot. The loop further comprises a return portion that extends from a discharge of the pump toward a suction of the pump. A sensor is disposed in the return portion of the loop and adapted to measure an electrical property that is indicative of total polar materials of said cooking oil.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Nonprovisional applicationSer. No. 14/752,278, filed on Jun. 26, 2015, which claimed priority fromU.S. Provisional Application No. 62/019,136, filed on Jun. 30, 2014, theentirety of which are each hereby incorporated by reference herein.

TECHNICAL FIELD

This disclosure relates to systems for measuring the quality of oilwithin a deep fat fryer system.

BRIEF SUMMARY

A first representative embodiment of the disclosure is provided. Theembodiment includes a system for measuring the state of degradation ofcooking oil in a deep fryer. The system includes at least one fryer potand a loop of piping that is fluidly connected to said at least onefryer pot for selectively allowing a flow of oil from the at least onefryer pot into the loop and for selectively allowing the cooking oil toreturn to said at least one fryer pot from the loop. A pump is providedfor urging the flow of cooking oil through the loop of piping andselectively to urge oil to return to the at least one fryer pot. Theloop further comprises a first valve that is positionable to a closedposition to prevent oil flow to or from the at least one fryer pot, andis positioned to an open position to allow flow to or from the at leastone fryer pot. The loop further comprises a return portion that extendsfrom a discharge of the pump toward a suction of the pump, wherein thereturn portion includes a second valve that is configured to selectivelyprevent or allow flow through the return portion. A sensor is disposedin fluid communication within the loop and adapted to measure anelectrical property that is indicative of total polar materials of saidcooking oil as the cooking oil flows within the loop of piping and pastsaid sensor.

Another representative embodiment of the disclosure is provided. Theembodiment includes a system for measuring the state of degradation ofcooking oil in a deep fryer. The system includes at least one fryer potand a loop of piping fluidly connected to said at least one fryer potfor selectively allowing flow of oil from the at least one fryer potinto the loop and for selectively allowing the cooking oil to return tosaid at least one fryer pot from the loop. A pump urges flow of cookingoil through the loop of piping and selectively to urge oil to return tothe at least one fryer pot. The loop further comprises a first valvethat is positionable to a closed position to prevent oil flow from theat least one fryer pot, and is positioned to an open position to allowflow from the at least one fryer pot. The loop further comprises asecond valve that is positionable to a closed position to prevent oilflow to the at least one fryer pot, and is positioned to an openposition to allow flow to the at least one fryer pot. The loop furthercomprises a recirculation portion that extends from a discharge of thepump toward a suction of the pump, wherein the recirculation portionincludes a third valve that is configured to selectively prevent orallow flow through the recirculation portion. A sensor is disposed influid communication within the loop and adapted to measure an electricalproperty that is indicative of the quality of the cooking oil within theloop of piping, wherein the sensor is disposed in the recirculationportion of the loop. During cooking operations within the fryer pot thefirst and second valves are in the closed position, and during anoperation of the sensor the first and second valves are shut.

Yet another representative embodiment of the disclosure is provided. Theembodiment includes a method of calibrating a sensor used in conjunctionwith a deep fat fryer. The method includes the steps of providing a deepfat fryer including a frypot configured to receive a quantity of oil forcooking a food product disposed therein, and a loop of piping fluidlyconnected to said at least one fryer pot for selectively allowing flowof oil from the at least one fryer pot into the loop and for selectivelyallowing the cooking oil to return to the at least one fryer pot fromthe loop. A pump is provided for urging the flow of cooking oil throughthe loop of piping and to selectively urge oil to return to the at leastone fryer pot, the loop further comprising a first valve disposed alonga flow path from the fryer pot toward a suction of the pump, and asecond valve disposed along a flow path from a discharge of the pump tothe fryer pot. The loop further comprising a recirculation portion thatextends from the discharge of the pump and toward a suction of the pump,wherein the recirculation portion includes a third valve that isconfigured to selectively prevent or allow flow through the returnportion. A sensor is provided that is disposed in fluid communicationwith the loop and adapted to measure an electrical property that isindicative of the quality of the cooking oil within the loop of piping.The method includes the step of providing a controller that receives asignal from the sensor that is indicative of the electrical propertymeasured by the sensor, and in use sending the signal from the sensor tothe controller. The method additionally includes the step of providing asecond sensor that is configured to interact with oil disposed withinthe deep fat fryer at a location remote from a position of the sensorwith in the loop, wherein the second sensor is configured to measure theelectrical property of the cooking oil that is indicative of the qualityof the cooking oil, the second sensor is configured to send a secondsignal to the controller that is indicative of the measured electricalproperty by the second sensor. The controller is configured to comparethe measurement of the second sensor received via the second signal withthe measurement of the sensor received via the signal from the sensorand the controller is configured to modify a calibration of the sensorbased upon a measured difference between the measurement by the sensorand the measurement by the second sensor.

Advantages of the present disclosure will become more apparent to thoseskilled in the art from the following description of the preferredembodiments of the disclosure that have been shown and described by wayof illustration. As will be realized, the disclosed subject matter iscapable of other and different embodiments, and its details are capableof modification in various respects. Accordingly, the drawings anddescription are to be regarded as illustrative in nature and not asrestrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a first schematic view of a fryer with an oil sensing system.

FIG. 2 is a schematic view of a fryer with a second oil sensing system.

FIG. 3 is a schematic view of a fryer with the oil sensing system ofFIG. 1 with a calibration system.

FIG. 4 is a schematic view of a fryer with another oil sensing system.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PRESENTLY PREFERREDEMBODIMENTS

Turning now to FIGS. 1-4, a system 10 for sensing the quality of oil ina deep fat fryer 1 is provided. The system 10 may be fluidly connectedto a deep fat fryer 1, such that the system 10 can be either bycontinuously, cyclically, or manually used to measure the quality of oillocated in the vat of the fryer, and can be operated during cookingoperations of the fryer 10 or when cooking operations are not occurringin the fryer 10.

The system 10 may be fluidly connected to at least one fryer pot(frypot) 100, which is configured to hold a volume of oil, which isnormally heated by one or more conventional electric heaters or gasburners which are in thermal communication with the frypot 100. Thefrypot 100 may be configured to receive one or more baskets 500 that areused to place food product within the heated oil to fry the food. Withcontinued use, the oil within the frypot tends to become degradedthrough prolonged interaction with the food product as well as due toother factors, such as oxidation, hydrolysis, etc.

The frypot 100 may be fluidly connected to the system 10 with one ormore oil outlets 21, and in some embodiments with one or more oil inlets22. The system 10 may include a filter 80, a pump 40, a recirculationsystem 26, and an oil sensor 60, each discussed below. The system 10 maybe formed as a loop 20 piping (such as rigid or flexible piping, orother types of conduit), that is configured to selectively allow theflow of oil from the at least one frypot 100, through the loop, andultimately return to the at least one frypot 100 (FIG. 1). The system 10may include a drain 4000, which may be controlled by a valve 4001 forselectively opening and closing the drain 4000. The valve 4001 may be amanual valve, or in some embodiments, the valve 4001 may be a remotelyoperated valve, such as a solenoid valve, and may be operable by acontroller 1000. As discussed elsewhere herein, the controller 1000 mayoperate the drain valve 4001 for several reasons, such as to dump oilfrom the system 10 (and therefore the frypot 100), to “feed and bleed”oil (i.e. simultaneous dumping of oil from the drain 4000 andreplacement with fresh oil from the storage vat 3000 (by operating thereplacement valve 3001)). As discussed elsewhere herein, the controller1000 may be programmed to automatically dump or feed and bleed oil fromthe system due to the measured quality of the oil by the sensor 60.

In some embodiments, the one or more oil outlets 21 from the frypot 100may be selectively isolated by a valve 48 (or valves 48) that may bemanual valves or remotely operable valves, such as solenoid valves.Similarly, the one or more oil inlets 22 to the frypot 100 may beselectively isolated by a valve 44 (or valves 44) that may be manualvalves or remotely operable valves, such as solenoid valves.

The sensor 60 may be an electrical sensor that is adapted tocontinuously measure one or more electrical parameters of the oil whichare directly indicative, or representative of the amount of impuritiesin the oil flowing through/past the sensor 60. For example, it is awell-known attribute of cooking oil to measure the total polarmaterials, or total polar compounds, therewithin and it is known thatthe amount of total polar materials/compounds increases as the life ofthe cooking oil decreases (i.e. the amount of total polarmaterials/compounds increases as the oil is used for longer timeperiods). The sensor 60 may be configured to continuously measure thecapacitance of the oil flowing past/through the sensor, which isrepresentative of the total polar materials/compounds in the oil, due tothe known proportionality between the total polar materials/compounds inthe oil and the dielectric constant of the oil. Still further, thesensor may be configured to measure voltage, resistance, dielectric,conductivity, or conductance of the oil, some or all of which may beindicative of total polar materials or other aspects of oil that relateto the overall quality of the oil, and in some embodiments, the sensormay be configured to measure more than one (or all) of these parameters.

The oil sensor may be a coaxial sensor, or a resonant sensor, or anothertype of sensor known in the art to be capable of sensing one or moreelectrical parameters of oil (such as those listed above) in order forthe sensor to determine the total polar compounds/materials within theoil to allow for an oil quality determination to be made, such as by thecontroller 1000.

The sensor 60 may provide a signal 1003 to the controller 1000 that isindicative of the measured electrical property of the oil. In someembodiments, the controller 1000 may receive the signal 1003 and performone or more of the functions discussed herein. For example, thecontroller 1000 may compare the measured electrical property of the oilto a programmed value (or range) of the electrical property. If thecontroller 1000 detects that the measured property is satisfactory (suchas it is above or below a setpoint, or it is within a programedacceptable range), the controller may provide an indication to the userthat the oil quality is acceptable, such as through a readout 1101 on adisplay 1100 associated with the fryer, or on a remote device 1004 thatcommunicates remotely 1002 (as schematically depicted in FIG. 1) withthe controller 1000 (or display 1100), such as through WiFi, Bluetoothor another available remote communication means 1110.

In some embodiments, and as shown in FIG. 1, the sensor 60 may send anoutput signal 1120 directly to the display 1100.

In some embodiments where the sensor 60 may be multiple sensors that cansimultaneously or non-simultaneously measure multiple differentproperties of oil, the user may control which property is sensed (ordisplayed) and the controller or the display may communicate with thesensor 60 to control the operation of the sensor, or otherwise directthe monitoring of the sensor. If the fryer is configured with anautomated filtration system, the controller 1000 may send a signal tothe automated filtration system that further filtration, or a batchfiltration if the system is adapted for continuous filtration of aportion of the oil within the system, is unnecessary.

If the controller 1000 determines that the measured property isunsatisfactory (such as above a setpoint or within a range indicative ofpoor oil quality) the controller may provide an alarm to the user. Thecontroller may also send a signal to an automated filtering system (whenprovided) indicating that a batch filter cycle is recommended (orperhaps required, such as immediately or after a current cooking cycleis completed). Further the controller 1000 could initiate an autotop-off system (when provided with the fryer) to automatically providenew oil to the frypot 100 and simultaneously open the drain valve 4001to “feed and bleed” the poor quality oil with new oil, and potentiallywithout interrupting cooking operations within the frypot. Moreover, ifthe measured property is above a setpoint, below a setpoint, or outsideof an acceptable range, the controller could turn off the fryer(potentially when an in-process cooking cycle is completed) and cause anautomatic draining (and disposal) of the frypot 100 and an automatedrefill of oil within the frypot (when an auto top-off system isprovided), or automatically drain, and dispose of the oil and signal tothe user that the frypot must be manually refilled.

The sensor 60 may be arranged to extend inline within the flow of oilthrough the system 10. In some embodiments, the sensor 60 may bedisposed within a recirculation line 26 of the system 10, which is aline that extends generally between the discharge 42 of the pump 40 andthe filter 80, and allows for oil to flow through the filter 80 and thepump without returning to the fryer pot 100. In some embodiments, therecirculation line 26 may include isolation valves 46, 49 on oppositesides of the sensor 60 (which may be manually or automaticallycontrolled, such as by the controller 1000) such that the system 10 maybe configured to isolate the sensor 60 and prevent oil flowtherethrough, or configured to allow flow through the sensor 60. Asdiscussed herein, the valves 44, 48 that selectively isolate the inletand outlet 22, 21 of the frypot, respectively, may be controlled inconjunction with the operation of the sensor 60 within the recirculationsystem. For example, when the sensor 60 is operated in the recirculationsystem, the valves 44, 48 may be shut so that the pump 60 urges oil flowonly through the recirculation system and the sensor 60 and the filter80 (with the valve positions schematically depicted in FIG. 2, e.g. “O”for open, “C” for closed). This configuration might be useful to monitorthe reduction of the capacitance (or the change in any other electricalcharacteristic discussed herein or otherwise known), and therefore totalpolar materials/compounds or any other electrical property of the oilmonitored by the sensor 60 (discussed above), which could provide anindication of the operability or effectiveness of the filter 80 overtime with continued flow.

Alternatively, in other embodiments, the sensor 60 may be operated withthe valves 44 and 48 open (and with the recirculation line isolationvalves 46, 49 open which allows for the oil from the frypot to befiltered continuously, as schematically depicted in FIG. 1, with thepossible valve positions, “O” for open, “C” for closed) and the portionof the oil discharged from the pump 40 that runs through therecirculation line 26 (instead of returning to the frypot 100) measured.This type of operation would allow for continuous filtration andmonitoring, if desired.

In some embodiments, the sensor 60 may be operated with the isolationvalves 46, 49 shut, such that the sensor 60 would measure the electricalcharacteristic of the slug of oil disposed proximate to the sensorbetween the valves 46, 49. This configuration may be appropriate forsensors that more accurately measure an electrical characteristic of oilthat is cooled significantly below normal cooking temperature of theoil. In some embodiments, the sensor 60 may be configured to measure theelectrical characteristic of the oil that is either flowing past thesensor or relatively still (i.e. when the isolation valves 46, 49 areshut).

In some embodiments shown in FIG. 4, one or more of the valves discussedabove and elsewhere herein may be replaced with three-way valves (744 or749) that may be manually operated, remotely operated by the controller1000 and/or automatically operated by the controller. For example, athree way valve 744 may be connected to each of the pump 40, the inletof the fryer 22, and the recirculation line 26. The valve 744 may beconfigured to direct oil from the pump either to the frypot 100 throughthe return line, or to the recirculation line 26 (and the sensor 60). Insome embodiments the valve 744 may be configured to allow flow from thepump 40 to both the frypot 100 through the return line and also to therecirculation line 26. In some embodiments, another three way valve 749in the recirculation line 26 that is connected to piping downstream ofthe sensor 60, the piping that returns oil to the filter pan 80, as wellas piping 27 that directs oil directly to the suction of the pump 40. Aswith valve 744, valve 749 may be manually operated, remotely operated bythe controller 1000, and/or automatically operated by the controller1000. The valve 749 may be configured to allow oil that flows throughthe sensor 60 to return to the filter pan 80, or to return directly tothe pump 60 through line 27. In some embodiments, the valve 749 can beconfigured to block oil flowing from the sensor 60, which would causeoil in the recirculation 26 to be still within the sensor 60. In otherembodiments, other three (or multiple way) valves may be provided, suchas a three way valve that combines the frypot drain valve 48 and thereplacement valve 3001, which would operate to selectively isolate thefrypot 100 (to prevent oil from draining therefrom), and to selectivelyallow replacement oil into the filter pan 80. Other three valves couldbe used.

In some embodiments and as shown in FIG. 1, in some embodiments, theloop may include a pipe 27 that extends from downstream of the sensor60, but before the downstream isolation valve 49 directly to the suctionof the pump 40 (or alternatively downstream of the downstream isolationvalve 49), therefore allowing flow through the sensor 60 that bypassesthe filter 80. In some embodiments the pipe 27 may be selectivelyisolated by a valve 45.

In some embodiments depicted in FIG. 3, a sensor (60′ or 60″) may beprovided in the drain line 4000 that allows for the oil to be disposedfrom the loop and ultimately from the fryer to be measured, in a similarmanner to the sensor 60, discussed above. The sensor 60′ (depictedupstream of the drain valve 4001) or the sensor 60″ (positioneddownstream of the drain valve 4001) may communicate with the controller1000 via a signal 11003, with the controller 1000 operating with respectto the sensor 60′ or 60″ in the same manner as the sensor 60 asdiscussed herein, including the calibration functionality as discussedherein. One of ordinary skill in the art will understand that the sensor60′ or 60″ may be beneficial to the operator to inform the operator ofthe quality (i.e. the value of the measured electrical property of theoil that is indicative of the quality of the oil) that is being drainedfrom the fryer, which might be useful such as in situations where it isimpractical or undesirable to send oil through the recirculation line 26for a measurement by the sensor 60.

The filter 80 may be one of many types of filter systems known in theart. For example, the filter may be a batch filter system, whichgenerally includes a filter vat 80, and one or more filter screens ormeshes or filter papers that are configured to mechanically particulatematter (such as crumbs) and impurities that normally collect in oilafter extended cooking of food product as well as after extended time atthe cooking temperature due to oxidation, hydrolysis or otherphenomenon. With a batch filtering process, oil, when not activelycooking a food product within the frypot 100, is drained to the filtervat 80, such that the oil passes through the various filtering screensor other filtering members. The filter vat 80 is normally filled whenoil is drained from the frypot 100 through valve 48. The pump 40 draws asuction from the filter vat 80 and urges the oil within the filter vatto flow through the filtering media and out of the filtering vat 80where it is pumped within the system.

Alternatively, the system may be used with a continuous filteringsystem. In such a system, volume of oil 600 from the frypot 100 flows(either naturally or with a pump (not shown)) out of the frypot 100 andinto the filtering system, where the oil flows through the filter vat 80and is ultimately pumped through the system, either returning to thefrypot 100 or through the recirculation line 26 and the sensor 60. Oneof ordinary skill in the art with a thorough review of the subjectspecification and figures will readily contemplate how to construct anappropriate batch filtering system or an appropriate continuousfiltering system that is configured to be readily used with an oilquality sensor 60 disposed within a recirculation line. One of ordinaryskill in the art would understand that such an alignment for an oilsensor 60, especially with a batch filtering system, would bebeneficial, such as for evaluation of the performance of the oil filter80.

For example, the operator (or a controller) could monitor the output ofthe oil sensor 60 as the pump 40 operates (with oil drained from thefrypot 100 and into the filter vat 80 and filtering system 10). If thepump 40 is run continuously for a set period of time, and the valves 44,48 are shut, the operator (or controller 1000) can measure theelectrical property of the oil (such as a property of total polarmaterials as discussed above or any other property of oil capable ofcontinuous monitoring), as monitored by the sensor 60 over time. If thesensed property improves (such as through an “improvement” of aparameter that is measured by the sensor over time toward a range or anoptimum level, which is an indication that the oil's ability toeffectively and efficiently cook foods is improving) over time, it maybe determined the filter 80 is operating properly. If the measuredproperty of the oil does not improve over time, then the filter 80 maynot be working properly. One of ordinary skill in the art will alsocontemplate that the rate of change of oil quality may also be anindication of the operability of the filter 80.

Turning now to FIG. 3, a system for calibration of the sensor 60 that isprovided within the recirculation line 26 of the fryer 1 is provided.The system may include all of the components of the filter system andthe recirculation system discussed above, such as a filter pan 80, loopisolation valves 44, 46, a sensor 60, and recirculation line isolationvalves 46, 49. The system may further include a controller 1000, which,as discussed above, may receive a signal 1003 from the sensor 60 that isindicative of the measured electrical property of the oil. In someembodiments the signal 1003 may be a raw digital or analog signal (suchas a voltage that changes based upon the magnitude of the measuredparameter) that is representative of the measurement taken by the sensor60, with the controller 1000 receiving the raw signal and converting itto a measured property. In other embodiments, the signal 1003 may be asignal that is the value of the actual parameter being measured. Inother words, in some embodiments, the sensor 60 may supply a signal 1003that must be processed and analyzed by the controller to determine thevalue of the parameter being measured (conductivity, dielectricconstant, etc.), and in some embodiments evaluated by the controller1000 to determine whether a signal, indication, or alarm should beprovided to the user (through signal 1001).

In either of the above possibilities initial and/or periodic or routinecalibration of the sensor 60 must be performed to ensure that themeasured electrical property (by the sensor 60) is indicative of thesame electrical property of the actual oil. It is known in the art thatthe electrical characteristics of sensors (and processing equipment) mayvary over time based upon factors such as changing internal resistance,fouling of the surface of a sensor's electrodes, or for other reasons.Due to these or any other changes in the sensor's operation (orpossibility changes in the wiring or path for an analog signaltransmission to the controller), it is important to periodically assessthe proper operation of the sensor and recalibrate the sensor asnecessary.

For example, in some embodiments, a portable sensor 6000 (shownschematically in FIG. 3) that measures the same electrical property ofthe oil as measured by the sensor may be provided. The sensor 6000 mayinclude a probe 6001 may be used to measure the electricalcharacteristic of the oil 600 within the fryer pot 100, and/or in otherembodiments the portable sensor 6000 may be used to measure theelectrical characteristic of the oil 600 within another position withinthe fryer 10, such as oil flowing (4002) from the drain 4000 (also shownschematically in FIG. 3). The portable sensor 6000 may provide a directreading of the measured electrical characteristic upon its display 6003.Alternatively or additionally, the portable sensor 6000 may provide asignal 6004 to the controller 1000 that is representative of themeasured electrical characteristic (either the signal 6004 being theactual value of the measured electrical characteristic, or a measurementthat is representative of the measured characteristic, similar to thesensor 60 as discussed above). In embodiments where the portable sensor6000 is used, assuming that the calibration of the portable sensor 6000was recently verified, the controller 1000 receives the value of themeasured parameter via the signal 6004 and compares the measuredparameter from the portable sensor 6000 with the value of the measuredparameter from the sensor 60 as received by the controller 1000. Ifthere is any difference between the values of the measured parameterfrom the portable sensor 6000 and the sensor 60, the controller 1000 canautomatically adjust the gain (or another adjustable parameter) of thesensor 60 to calibrate the output of the sensor 60, or alternatively oradditionally modify the controller's processing of the signal 1003received from the sensor 60 such that the value of the measuredparameter of the sensor 60 is consistent with the measured value of thesensor 6000, in order for the measurement taken by the sensor 60 toreflect the “accurate” measurement of the same parameter using theportable sensor 6000.

Various calibration techniques that could be implemented by thecontroller 1000 to adjust the calibration of the sensor 60 (suchadjusting the gain, or the input voltage of the sensor 60) are wellknown in the art and will not be repeated herein for the sake ofbrevity. In some embodiments, the adjustment could be made to theoperation of the sensor 60, such as adjusting the gain of the sensor,which would result in the sensor 60 sending a differing signal 1003 tothe controller after the adjustment, while in other embodiments, thecalibration may occur within the controller 1000, such that thecontroller changes the way that the signal 1003 received from the sensor60 is processed to result in the value of the measured parameter ascalculated by the controller 1000. In some embodiments where thecalibration changes are made directly to the sensor's 60 operation, thechanges (or instructions for the sensor 60 to change) are sent to thesensor 60 automatically via the signal path 1003.

Alternatively, the controller 1000 may generate and provide the userwith instructions to manually adjust the sensor 60 to properly calibratethe sensor. The instructions may be via a display 1100 upon the fryer,or a message that is relayed to the user via wireless communication,WiFi, Bluetooth, and via different types of information exchange methods(email, text, etc.).

In some embodiments, the controller 1000 may store calibration events,and in some embodiments index calibration events, such as with adate/time stamp, for future reference. In some embodiments, when ameasurement of an electrical parameter of the oil by the sensor 60 isoutside of a specification, or the controller detects a moving trend inthe measured parameter by the sensor 60, the controller may referencethe calibration history of the sensor 60, and suggest to the user that acalibration may be called for (using the portable sensor 6000), beforeor in conjunction with the controller 1000 taking action with respect tothe oil, such as automatically initiating a filter event, dumping oilthrough the drain 4000, or feeding and bleeding oil, or the like.

In other embodiments, the portable sensor 6000 may communicate with thesensor 60 directly (such as via a signal path 6005 shown schematicallyin FIG. 3), in addition to or instead of the communication with thecontroller 1000. In these embodiments, the sensor 60 may be programmedto self-calibrate based upon the signal received from the portablesensor 6000, rather than be calibrated based upon instructions receivedfrom the controller 1000. Other than this difference, the calibration ofthe sensor 60 based upon signals received from the portable sensor 6000is consistent with the embodiments described above.

In some embodiments, as shown in FIG. 3, the fryer 1 may include one ormore oil quality sensors 7000 that are positioned to monitor a desiredparameter of oil within the fryer pot 100 (or within one fryer pot 100of a fryer set up where multiple neighboring fryer pots 100 are fluidlyconnected to one filtration system and oil sensor 60 disposed within arecirculation line 26 within a filtration system). The one or more oilquality sensors 7000 may be configured to measure the same parameter ofoil as the sensor 60 that is positioned in the recirculation line 26,while in other embodiments, one or more sensors 7000 may be configuredto measure a different parameter of oil as the sensor 60. The one ormore sensors 7000 may communicate with the controller 1000 via a path7001, which may be hard wired or wireless. In other embodiments, otherthan the difference between the sensor 7000 which may be rigidly mountedupon the fryer pot 100 to directly (or indirectly) measure one or moreelectrical characteristics of the oil within the fryer pot, theoperation of the sensor 7000 and the method for calibration of thesensor 60 based upon a measurement by the sensor 7000 is consistent withthe description of the operation and calibration based upon the portablesensor 6000 described above. In some embodiments, the sensor 7000provides the measurement(s) of the electrical parameters of oil qualityto the controller, with any automated operations of the fryer from thecontroller 1000, or indications to the user regarding oil quality basedupon the measurements taken from sensor 7000. In some embodiments, theportable sensor 6000 (discussed elsewhere herein) may be used forcalibrating the sensor 7000, in the same manner as discussed herein withrespect to the calibration of sensor 60.

The following numbered paragraphs are provided:

Numbered Paragraph 1: A system for measuring the state of degradation ofcooking oil in a deep fryer comprising:

-   -   at least one fryer pot;    -   a loop of piping fluidly connected to said at least one fryer        pot for selectively allowing flow of oil from the at least one        fryer pot into the loop and for selectively allowing the cooking        oil to return to said at least one fryer pot from the loop;    -   a pump for urging the flow of cooking oil through the loop of        piping and selectively to urge oil to return to the at least one        fryer pot,    -   the loop further comprising a first valve that is positionable        to a closed position to prevent oil flow to or from the at least        one fryer pot, and is positioned to an open position to allow        flow to or from the at least one fryer pot,    -   the loop further comprises a return portion that extends from a        discharge of the pump toward a suction of the pump, wherein the        return portion includes a second valve that is configured to        selectively prevent or allow flow through the return portion;    -   a sensor disposed in fluid communication within the loop and        adapted to measure an electrical property that is indicative of        the quality of the cooking oil within the loop of piping,        wherein the sensor is disposed in the return portion of the        loop.

Numbered Paragraph 2: The system of numbered paragraph 1, wherein thesensor is configured to measure an electrical property that isindicative of the total polar materials of the cooking oil.

Numbered Paragraph 3: The system of numbered paragraph 1, wherein thesensor is configured to measure the electrical property of the cookingoil when the cooking oil flows past the sensor.

Numbered Paragraph 4: The system of numbered paragraph 1, wherein thesensor is configured to measure the electrical property of the cookingoil when the cooking oil is relatively stationary next to the sensor.

Numbered Paragraph 5: The system of numbered paragraph 1, wherein thesensor is configured to measure the electrical property of the cookingoil when the cooking oil flows past the sensor and when the cooking oilis relatively stationary next to the sensor.

Numbered Paragraph 6: The system of numbered paragraph 1, wherein saidsensor is selected from a capacitance sensor, a voltage sensor, aresistance sensor, a dielectric sensor, a conductivity sensor, or aconductance sensor.

Numbered Paragraph 7: The system of numbered paragraph 1, wherein saidsensor is a coaxial sensor.

Numbered Paragraph 8: The system of numbered paragraph 1, furthercomprising an oil filtration system that is disposed in fluidcommunication with the loop.

Numbered Paragraph 9: The system of numbered paragraph 1, wherein thefirst valve is located downstream from a discharge of the pump.

Numbered Paragraph 10: The system of numbered paragraph 1, wherein thesensor is configured to measure two or more of capacitance, voltage,resistance, dielectric, conductivity, or conductance of oil thatcontacts the sensor.

Numbered Paragraph 11: The system of numbered paragraph 1, wherein thesensor is disposed upstream of a suction of the pump.

Numbered Paragraph 12: The system of numbered paragraph 1, furthercomprising a controller that receives a signal from the sensorindicative of the measured electrical property of the oil.

Numbered Paragraph 13: The system of numbered paragraph 12, wherein thefirst and second valves are remotely operable by the controller, and thecontroller is configured to selectively operate one or both of the firstand second valves based upon the measured electrical property of theoil.

Numbered Paragraph 14: The system of numbered paragraph 13, wherein theloop is fluidly connected to a source of replacement oil, and whereinthe loop further comprises a drain, wherein the controller is configuredto selectively open the drain to allow cooking oil within the loop todrain from the loop and to selectively allow replacement oil to flowinto the loop, wherein the controller selectively allows the cooking oilto drain from the loop and allows replacement oil to flow into the loopbased upon the measured electrical property of the oil.

Numbered Paragraph 15: The system of numbered paragraph 1, furthercomprising a third valve positioned within the return portion andlocated between the sensor and an oil filtration system, such that oilflowing through the return portion flows first through the sensor, thenthrough the third valve, and then into the oil filtration system.

Numbered Paragraph 16: The system of numbered paragraph 15, wherein thethird valve is operable by a controller, wherein the third valve isopened when the second valve is opened by the controller, and the thirdvalve is shut when the second valve is shut by the controller.

Numbered Paragraph 17: The system of numbered paragraph 1, furthercomprising a display or an alarm in electrical communication with saidsensor for indicating a parameter of the oil that is representative ofthe measured electrical property of the oil.

Numbered Paragraph 18: The system of numbered paragraph 1, wherein theloop is connected to the fryer pot with a first connection that is influid communication with a suction of the pump and the loop is connectedto the fryer pot with a second connection that is in fluid communicationwith a discharge of the pump, wherein the first valve is disposed uponthe first connection, and further comprising a third valve that isdisposed between the discharge of the pump and the fryer pot.

Numbered Paragraph 19: The system of numbered paragraph 12, furthercomprising a second sensor, the second sensor being configured tointeract with oil disposed within the deep fat fryer at a locationremote from the return portion, wherein the second sensor is adapted tomeasure the electrical property of the cooking oil that is indicative ofthe quality of the cooking oil, that is measured by the sensor, whereinthe second sensor is configured to send a signal to the controller thatis representative of the measurement of the electrical property of thecooking oil by the second sensor, and the controller is configured tocompare the measurement of the second sensor with a measurement of theelectrical property of the cooking oil received from the sensor, and thecontroller is configured to modify a calibration of the sensor basedupon a determined difference between the measurement by the sensor andthe measurement by the second sensor.

Numbered Paragraph 20: The system of numbered paragraph 19, wherein thecontroller is configured to send a signal to the sensor to modify asetting of the sensor to modify the calibration of the sensor.

Numbered Paragraph 21: The system of numbered paragraph 19, wherein thecontroller is configured to adjust its settings for processing a signalreceived from the sensor that is indicative of the quality of thecooking oil within the loop of piping to modify the calibration of thesensor.

Numbered Paragraph 22: The system of numbered paragraph 19, wherein thesecond sensor sends the signal to the controller wirelessly.

Numbered Paragraph 23: A system for measuring the state of degradationof cooking oil in a deep fryer comprising:

-   -   at least one fryer pot;    -   a loop of piping fluidly connected to said at least one fryer        pot for selectively allowing flow of oil from the at least one        fryer pot into the loop and for selectively allowing the cooking        oil to return to said at least one fryer pot from the loop;    -   a pump for urging the flow of cooking oil through the loop of        piping and selectively to urge oil to return to the at least one        fryer pot,    -   the loop further comprising a first valve that is positionable        to a closed position to prevent oil flow from the at least one        fryer pot, and is positioned to an open position to allow flow        from the at least one fryer pot,    -   the loop further comprising a second valve that is positionable        to a closed position to prevent oil flow to the at least one        fryer pot, and is positioned to an open position to allow flow        to the at least one fryer pot,    -   the loop further comprises a recirculation portion that extends        from a discharge of the pump toward a suction of the pump,        wherein the recirculation portion includes a third valve that is        configured to selectively prevent or allow flow through the        recirculation portion;    -   a sensor disposed in fluid communication within the loop and        adapted to measure an electrical property that is indicative of        the quality of the cooking oil within the loop of piping,        wherein the sensor is disposed in the recirculation portion of        the loop,    -   wherein during cooking operations within the fryer pot the first        and second valves are in the closed position, and during an        operation of the sensor the first and second valves are shut.

Numbered Paragraph 24: The system of numbered paragraph 23, furthercomprising a fourth valve positioned within the recirculation portionand disposed on an opposite side of the sensor from the third valve.

Numbered Paragraph 25: The system of numbered paragraph 24, wherein thethird and fourth valves are open during operation of the sensor.

Numbered Paragraph 26: The system of numbered paragraph 24, wherein thethird and fourth valves are shut during operation of the sensor.

Numbered Paragraph 27: The system of numbered paragraph 23, wherein thesensor is configured to measure an electrical property that isindicative of the total polar materials of the cooking oil.

Numbered Paragraph 28: The system of numbered paragraph 23, wherein thesensor is selected from a capacitance sensor, a voltage sensor, aresistance sensor, a dielectric sensor, a conductivity sensor, or aconductance sensor.

Numbered Paragraph 29: The system of numbered paragraph 23, furthercomprising a controller that receives a signal from the sensorindicative of the measured electrical property of the oil.

Numbered Paragraph 30: The system of numbered paragraph 29, wherein thefirst and second valves are remotely operable by the controller, and thecontroller is configured to selectively operate one or both of the firstand second valves based upon the measured electrical property of theoil.

Numbered Paragraph 31: The system of numbered paragraph 30, wherein theloop is fluidly connected to a source of replacement oil, and whereinthe loop further comprises a drain, wherein the controller is configuredto selectively open the drain to allow cooking oil within the loop todrain from the loop and to selectively allow replacement oil to flowinto the loop, wherein the controller selectively allows the cooking oilto drain from the loop and allows replacement oil to flow into the loopbased upon the measured electrical property of the oil.

Numbered Paragraph 32: The system of numbered paragraph 29, furthercomprising a second sensor, the second sensor being configured tointeract with oil disposed within the deep fat fryer at a locationremote from the recirculation portion, wherein the second sensor isadapted to measure the electrical property of the cooking oil that isindicative of the quality of the cooking oil that is measured by thesensor, wherein the second sensor is configured to send a second signalto the controller that is representative of the measurement of theelectrical property of the cooking oil by the second sensor, and thecontroller is configured to compare the measurement of the second sensorreceived via the second signal with a measurement of the electricalproperty of the cooking oil received from the sensor via the signal, andthe controller is configured to modify a calibration of the sensor basedupon a measured difference between the measurement by the sensor and themeasurement by the second sensor.

Numbered Paragraph 33: The system of numbered paragraph 32, wherein thecontroller is configured to send a signal to the sensor to modify asetting of the sensor to modify the calibration of the sensor.

Numbered Paragraph 34: The system of numbered paragraph 32, wherein thecontroller is configured to adjust its settings for processing a signalreceived from the sensor that is indicative of the quality of thecooking oil within the loop of piping to modify the calibration of thesensor.

Numbered Paragraph 35: The system of numbered paragraph 32, wherein thesecond sensor sends the signal to the controller wirelessly.

Numbered Paragraph 36: A method of calibrating a sensor used inconjunction with a deep fat fryer, comprising:

-   -   providing a deep fat fryer including a fryer pot configured to        receive a quantity of oil for cooking a food product disposed        therein, and a loop of piping fluidly connected to said at least        one fryer pot for selectively allowing flow of oil from the at        least one fryer pot into the loop and for selectively allowing        the cooking oil to return to the at least one fryer pot from the        loop, a pump for urging the flow of cooking oil through the loop        of piping and to selectively urge oil to return to the at least        one fryer pot, the loop further comprising a first valve        disposed along a flow path from the fryer pot toward a suction        of the pump, and a second valve disposed along a flow path from        a discharge of the pump to the fryer pot,    -   the loop further comprising a recirculation portion that extends        from the discharge of the pump and toward a suction of the pump,        wherein the recirculation portion includes a third valve that is        configured to selectively prevent or allow flow through the        recirculation portion,    -   providing a sensor disposed in fluid communication with the loop        and adapted to measure an electrical property that is indicative        of the quality of the cooking oil within the loop of piping,    -   providing a controller that receives a signal from the sensor        that is indicative of the electrical property measured by the        sensor, and in use sending the signal from the sensor to the        controller,    -   providing a second sensor that is configured to interact with        oil disposed within the deep fat fryer at a location remote from        a position of the sensor within the loop, wherein the second        sensor is configured to measure the electrical property of the        cooking oil that is indicative of the quality of the cooking oil        that is measured by the sensor, the second sensor is configured        to send a second signal to the controller that is indicative of        the measured electrical property by the second sensor;    -   wherein the controller is configured to compare the measurement        of the second sensor received via the second signal with the        measurement of the sensor received via the signal from the        sensor,    -   wherein the controller is configured to modify a calibration of        the sensor based upon a measured difference between the        measurement by the sensor and the measurement by the second        sensor.

Numbered Paragraph 37: The method of numbered paragraph 36, wherein thesensor is disposed within the recirculation portion of the loop.

Numbered Paragraph 38: The method of numbered paragraph 36, wherein thesecond sensor is configured to send a wireless signal to the controllerthat is the second signal.

Numbered Paragraph 39: The method of numbered paragraph 36, wherein therecirculation portion of the loop comprises a third valve that isdisposed between the discharge of the pump and the sensor, and whereinthe controller is configured to open the third valve when a sensingoperation by the sensor is desired.

While the preferred embodiments of the disclosed have been described, itshould be understood that the invention is not so limited andmodifications may be made without departing from the disclosure. Thescope of the disclosure is defined by the appended claims, and alldevices that come within the meaning of the claims, either literally orby equivalence, are intended to be embraced therein.

1. A system for measuring the state of degradation of cooking oil in a deep fryer comprising: at least one fryer pot; a loop of piping fluidly connected to said at least one fryer pot for selectively allowing flow of oil from the at least one fryer pot into the loop and for selectively allowing the cooking oil to return to said at least one fryer pot from the loop; a pump for urging the flow of cooking oil through the loop of piping and selectively to urge oil to return to the at least one fryer pot, the loop further comprising a first valve that is positionable to a closed position to prevent oil flow to or from the at least one fryer pot, and is positioned to an open position to allow flow to or from the at least one fryer pot, the loop further comprises a return portion that extends from a discharge of the pump toward a suction of the pump, wherein the return portion includes a second valve that is configured to selectively prevent or allow flow through the return portion; a sensor disposed in fluid communication within the loop and adapted to measure an electrical property that is indicative of the quality of the cooking oil within the loop of piping, wherein the sensor is disposed in the return portion of the loop. 